Do you have a 12-1/2" square ruler to square them up, all to the same size. If some are 1" or more smaller, you will have to add to them to make them the same size. Or make them all 11-1/2" or whatever your size is. You do not have to make a 12-1/2" square all over a quilt. If you don't have a square ruler, take printer paper and make one. Use the straight sides where you can. I hope this helps. I personally would add to the squares to make them all 12-1/2". You need 12-1/2" to be able to sew 1/4" on each side. Good luck.